Conservative Leader Andrew Scheer responds to a question during a news conference in Montreal on April 19, 2018. The parliamentary budget office released a report this morning saying Bill C-394, which would bring in a tax credit for those on parental leave, would result in foregone revenues of $607.6 million in 2018-19. PAUL CHIASSON / THE CANADIAN PRESS

A new report by the parliamentary budget watchdog says Conservative Leader Andrew Scheer’s proposed tax credit for parents would cost federal coffers more than $600 million in the first year — and possibly even more.

The parliamentary budget office released a report this morning saying if passed, Bill C-394 — which includes a tax credit for those on parental leave — would mean foregone revenues of $607.6 million in 2018-19.

Because not all families would be able to claim the total amount in the first year, an additional $261 million in costs would likely be added in future years.

In its 2018 budget, the Trudeau government announced changes to provide additional weeks of parental leave for families with both parents taking time off to care for a newborn.

The PBO estimates Scheer’s proposed measure would increase the cost of the Liberal government’s benefit by an additional $24.1 million.

Scheer tabled his private member’s bill last month, promoting it as a way to help new parents offset any taxes owing on their maternity and parental leave.